From: Johannes Berg Date: Tue, 30 Jul 2013 22:38:42 +0200 Subject: nl80211: fix another nl80211_fam.attrbuf race Origin: https://git.kernel.org/cgit/linux/kernel/git/jberg/mac80211.git/commit/?id=c319d50bfcf678c2857038276d9fab3c6646f3bf This is similar to the race Linus had reported, but in this case it's an older bug: nl80211_prepare_wdev_dump() uses the wiphy index in cb->args[0] as it is and thus parses the message over and over again instead of just once because 0 is the first valid wiphy index. Similar code in nl80211_testmode_dump() correctly offsets the wiphy_index by 1, do that here as well. Cc: stable@vger.kernel.org Reported-by: Ben Hutchings Signed-off-by: Johannes Berg --- net/wireless/nl80211.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 25d217d..3fcba69 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -441,10 +441,12 @@ static int nl80211_prepare_wdev_dump(struct sk_buff *skb, goto out_unlock; } *rdev = wiphy_to_dev((*wdev)->wiphy); - cb->args[0] = (*rdev)->wiphy_idx; + /* 0 is the first index - add 1 to parse only once */ + cb->args[0] = (*rdev)->wiphy_idx + 1; cb->args[1] = (*wdev)->identifier; } else { - struct wiphy *wiphy = wiphy_idx_to_wiphy(cb->args[0]); + /* subtract the 1 again here */ + struct wiphy *wiphy = wiphy_idx_to_wiphy(cb->args[0] - 1); struct wireless_dev *tmp; if (!wiphy) {